Epicyclic gears have been used in winches before--see for example U.S. Pat. No. 3,682,442 and GB-A-2253199 (WO-A-9106502).
The first of these provides an epicyclic gear in which the axes of rotation of planet gears are borne on a rotatable carrier which intervenes between the central drive shaft and the winch drum which is to be driven. Oppositely-directed sprag clutches between the drive shaft and the carrier enable either 1:1 direct drive to be transmitted through the planetary gearing, the carrier of which is effectively locked stationary by the sprag clutches in one direction of rotation of the shaft, or with a moderate reduction, 1:4 being mentioned, through mutual relative rotation of all of the shaft, the carrier and the drum.
The second is concerned with the provision of multiple gear trains capable of giving extremely high reductions, provided in a detachable gearbox mounted at the head of the winch.